Method and apparatus for producing compressed air and water pumping apparatus utilizing the produced air

ABSTRACT

Compressed gas obtained from a recovery vessel (30) is used to provide the motive power to drive a water pump to return water that has been used for hydro-electric power generation from a lower reservoir (82) to an upper reservoir (80). &lt;IMAGE&gt;

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for the production ofcompressed air, to an apparatus for carrying out the method, and to awater pumping apparatus for use in hydroelectric power generationutilizing the compressed air produced by the method and apparatus.

2. Description of Prior Art

Energy available at present in the world relies heavily on coal,petroleum, and nuclear power, the use of which often results inenvironmental destruction. On the other hand, hydroelectric power, windpower or wave power whose power, has nothing to do with environmentaldestruction, has little or no prospect of great development.

OBJECTS AND SUMMARY OF THE INVENTION

One object of the present invention is to provide a method for producingcompressed air serving as air expansion energy from natural resourcesand an apparatus for carrying out the method.

Another object of the present invention is to provide a water pumpingapparatus for use in hydroelectric power generation utilizing airexpansion energy of the compressed air obtained by the aforementionedmethod and apparatus.

To achieve the objects described above, from one aspect of the presentinvention there is provided a method for producing compressed air, whichcomprises sealing air in a container capable of reducing its volume byan external hydraulic pressure, attaching a weight having a largerspecific gravity than water to the container to sink the container deepunder water, inserting under pressure compressed air produced when thevolume of the container is reduced by hydraulic pressure into a recoveryvessel connected to the container via a check valve, separating theweight from the container to cause the container to float on the waterby the action of buoyancy, and recovering the compressed air from therecovery vessel.

From another aspect of the present invention, there is provided anapparatus for carrying out the aforementioned method, which comprises acontainer having an air chamber in which air is sealed and capable ofreducing the volume of the chamber by external hydraulic pressure, arecovery vessel connected to the container via a check valve forrecovering compressed air produced when the volume of the chamber isreduced by the hydraulic pressure, and a weight attached to thecontainer for sinking the container and vessel deep under water.

From still another aspect of the present invention, there is provided awater pumping apparatus for use in hydroelectric power generationutilizing compressed air, which comprises a container interposed betweenan upstream water reservoir of a hydroelectric power generatingapparatus and a downstream water reservoir of the hydroelectric powergenerating apparatus for storing the water subjected to hydroelectricpower generation, a piston slidably accommodated within the containerfor dividing the interior of the container into a water tank chamber andan air expansion chamber, a water inlet tube connected to the water tankchamber via a first control valve for regulating the flow rate of thewater supplied from the downstream water reservoir into the water tankchamber, a water feed pipe connected to the water tank chamber via asecond control valve for regulating the flow rate of the water fed underpressure from the water tank chamber into the upstream water reservoir,and a recovery vessel containing compressed air therein and connectedvia a flow regulating valve to the air expansion chamber for dischargingthe compressed air contained in the recovery vessel into the airexpansion chamber to cause the piston to slide in a direction increasingthe volume of the air expansion chamber.

The present invention utilizes three physical properties, i.e. the factthat a substance at a high position has a higher potential energy than asubstance at a low position, that buoyancy acts on a substance in freshwater and that hydraulic pressure increases in proportion to the depthof water.

To be specific, a container having air sealed therein is sunk deep underwater by using a weight having a larger specific gravity than water,thereby compressing the air in the container by means of hydraulicpressure, the weight is caused to be free from the container to allowthe container to float on the water by the action of buoyancy of abuoyant body, and then the compressed air is recovered from thecontainer. Thus, the present invention uses specific gravity, hydraulicpressure and buoyancy, all obtained from natural resorces.

The air expansion energy of the recovered compressed air can be appliedto a hydroelectric power generating apparatus. In this case, the wateronce subjected to power generation can be repeatedly recycled.Therefore, the hydraulic power generation otherwise limited by theamount of rain water can be utilized to the maximum possible extent. Inaddition, the hydroelectric power generation can be applied to privatepower generation in a multistory building, for example. The airexpansion energy of the compressed air can be used in the form of powerfor driving and propelling vehicles, or as a cooling means, utilizingthe phenomenon that when gas is expanded it absorbs the environmentalheat. When the compressed air is mixed with fuel in an internalcombustion engine, the amount of the fuel can be reduced. The compressedair is also applicable to a sprayer. Thus, since the air expansionenergy of the compressed air can be converted into various kinds ofenergy, the present invention can reduce the amount of fossil fuels usedat present to a great extent.

The above and other objects, characteristic features and advantages ofthe present invention will become more apparent from the description tobe given hereinbelow with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross section illustrating one embodiment of anapparatus for producing compressed air according to the presentinvention, with a clamping device omitted.

FIG. 2 is a schematic cross section illustrating the apparatus of FIG. 1with a compressed air recovery vessel omitted.

FIG. 3 is a schematic cross section illustrating another embodiment ofan apparatus for producing compressed air according to the presentinvention.

FIG. 4 is a schematic cross section illustrating one embodiment of awater pumping apparatus for use in hydroelectric power generationutilizing the compressed air according to the present invention.

FIG. 5 is a schematic cross section illustration of another embodimentof a water pumping apparatus according to the present invention.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, the present invention will be described in detail with reference tothe accompanying drawings.

FIGS. 1 and 2 are schematic cross-sectional views illustrating oneembodiment of the apparatus for producing compressed air according tothe present invention. The apparatus 1 includes a container body 10having an air chamber 12 sealing air therein, and is capable of reducingits volume by hydraulic pressure. A compressed air recovery vessel 30 isconnected to the air chamber 12 via a check valve 32 and adapted toreceive the compressed air therein when the volume of the air chamber 12is reduced by hydraulic pressure. A weight 40 is mounted on thecontainer body 10 and adapted to sink the container body 10 and recoveryvessel 30 deep under water.

The cylindrical container body 10 has a compression piston 14 disposedtherein dividing the interior of the container body 10. The piston 14 isslidable upward and downward along the inner wall of the container body10 in the air chamber 12. A water chamber 16 is formed with a pluralityof water inlet ports 18 for introducing water thereinto. When thecontainer body 10 is caused to sink deep under water, the external waterenters the water chamber 16 disposed on the upper side of thecompression piston 14 through the water inlet ports 18 under pressure.The compression piston 14 moves toward the air chamber 12, urged by thehydraulic pressure of the water entering the water chamber 16 to therebycompress the air in the air chamber 12. The air chamber 12 is connectedto a compressed air recovery vessel 30 through a connecting tube 34. Theconnecting tube 34 is provided with a check valve 32. The compressed airrecovery vessel 30 has a very small volume compared with that of the airchamber 12 before it is reduced in volume, so that the compressed airsupplied into the recovery vessel 30 can be maintained intact. The checkvalve 32 acts such that when the pressure in the air chamber 12 ishigher than that in the compressed air recovery vessel 30, the air inthe air chamber 12 is permitted to flow into the air recovery vessel 30and that when the pressure relation is reversed, the compressed air inthe air recovery vessel 30 does not flow back into the air chamber 12.The recovery vessel 30 can be detached from the container body 10 forreplacement.

FIG. 3 shows another embodiment of the apparatus for producingcompressed air according to the present invention. In this embodiment,the outer wall of the container body 10 can be deformed to be expandedand contracted in the vertical direction by the external hydraulicpressure. The inside space of the container body 10 serves as an airchamber 12. When the outer wall is contracted by the external hydraulicpressure, the volume of the air chamber 12 can be reduced. The structureof the container body 10 will be described in more detail. It isconstructed in a sealed state such that an upper plate 21 and a lowerplate 22 are joined together through a cloth material 24 and such that aplurality of annular reinforcement member 24 are sewn to the clothmember 26 so that it is expanded into a cylindrical configuration whenair having a higher pressure than the atmospheric pressure is introducedinto the air chamber 12. The cloth material 24 is formed of a materialwhich is strong in tensile stress and is water- and air-impermeable. Thereinforcement members 26 are strong against a compressive force and arehardly deformed. The air chamber 12 is provided with an air inlet valve28 adapted to take air into the air chamber 12. The upper plate 21 ofthe container body 10 is connected to a compressed air recovery vessel30 via a connecting tube 34. The connecting tube 34 is provided with acheck valve 32 which has the same function as the check valve 32 of theprevious embodiment. Although the container body 10 of this embodimenthas a hollow cylindrical configuration, it is preferable that it has ahollow spherical configuration so that it can bear the hydraulicpressure of the deep sea.

In any of the embodiments described above, a weight 40 is detachablyattached to the container body 10 in order to sink the container body 10deep under water. The weight 40 is detached from the container body 10when the volume of the air chamber 12 is reduced to the maximum possibleextent by hydraulic pressure. The container body 10 of the embodimentshown in FIGS. 1 and 2 is provided with a buoyant body 70 so that it canfloat on the water by means of buoyancy when the sink weight 40 has beendetached from the container body 10, whereas the compressed air recoveryvessel 30 of the embodiment shown in FIG. 3 concurrently serves as thebuoyant body 70, which will be described later.

The weight 40 is detached from the container body 10 when the volume ofthe air chamber 12 is reduced to the maximum possible extent, i.e. whenthe surface of the compression piston 14 comes into contact with thebottom of the air chamber 12 in the embodiment of FIGS. 1 and 2 or whenthe upper and lower plates 21 and 22 come into contact with each otherin the embodiment of FIG. 3.

In the embodiment shown in FIGS. 1 and 2, the weight 40 is accommodatedwithin a weight mounting device 42, which comprises a casing 44 having abottom portion 46 capable of being opened by the weight of the weight40. The bottom portion 46 is closed by a wire 48 clamped by a clampingdevice 50 without being accidentally opened.

The clamping device 50 comprises wrench like holding metal pieces 52which have clamp portions and proximal portions pivoted on a pin 54.When the proximal portions are away from each other, the clamp portionsare also away from each other. One of the proximal portions is fixed toa lower part of the container body 10, whereas the other of the proximalportions is left free. Between the proximal portions a spring body 56 isinterposed for biasing the free proximal portion in a direction awayfrom the fixed proximal portion. A lock lever 58 is provided to lock thefree proximal portion so as not to be moved away from the fixed proximalend by the biasing force of the spring body 56. An unlocking pin 60 hasan upper end thereof projecting into the a air chamber 12 and the lowerend thereof engaged with the lock lever 58. Therefore, when the upperend of the unlocking pin 60 is depressed by the compression piston 14,the lock lever 58 is disengaged from the free proximal end and, as aresult, the free proximal end is biased by the biasing force of thespring body 56 in the direction away from the fixed proximal end to openthe clamp portions. Consequently, the wire 48 is released from the clampportions and the bottom portion 46 of the casing 42 is opened by theweight of the weight 40, thereafter the weight 40 is discharged out ofthe casing 42. Gravel on the seashore can be used as the weight 40.

The same clamping device 50 as in the embodiment of FIGS. 1 and 2 isused in the embodiment of FIG. 3, provided that the weight 40 is formedof a bag filled with gravel and suspended from the clamping device 50.

In the apparatus shown in FIGS. 1 and 2, both the container body 10 andthe casing 44 are provided with buoyant chambers acting as the buoyantbody 70. Since a compressed stress applied to the buoyant chambersbecomes larger in proportion as the apparatus sinks deeper under water,the structural members constituting the buoyant chambers are required tobe rigid. In order to make the difference between the internal pressureand the external pressure as small as possible at the bottom of thewater level which the apparatus reaches, it is desirable to fill thebuoyant chambers with compressed air in advance.

In the apparatus of FIG. 3, the compressed air recovery vessel 30 servesconcurrently as the buoyant body 70, which has a hollow sphericalconfiguration and is connected to an upper portion of the container body10 via rods 72. Due to the dual function of the recovery vessel 30, thepressure of the air contained therein is increased by repeating therecovery operation in view of the volume of the recovery vessel 30 and,therefore, the apparatus of FIG. 3 can bear the higher hydraulicpressure in deeper water and can be suitably used for obtaining acompressed air of high pressure.

The operation of the apparatus of FIGS. 1 and 2 will now be described.The compression piston is pulled to the highest position, and then theair recovery vessel is attached to the container body 10. After thebottom portion of the casing 44 is closed, the weight 40 is introducedinto the casing 44. The casing 44 is then attached to the lower part ofthe container body 10. Thereafter the apparatus is hung above thesurface of the sea by means of a hanging chain (not shown) and thenseparated from the hanging chain. As a result, the whole apparatus issunk deep under the water by gravity. At that time, water flows into thewater chamber 16 through the water inlet ports 18 due to hydraulicpressure to push the compression piston 14 down, thereby compressing theair in the air chamber 12. The hydraulic pressure increases as theapparatus sinks deeper, and the lower end of the compression piston 14is eventually brought to the bottom portion of the air chamber 12. Thus,all air in the air chamber 12 is inserted into the recovery vessel 30under pressure. Since the recovery vessel 30 is provided with the checkvalve 32, a decrease of air pressure in the air chamber 12 does notcause the compressed air in the recovery vessel 30 to flow back to theair chamber 12. When the lower end of the compression piston 14 reachesthe bottom portion of the air chamber 12, the clamped state of theclamping device 50 is released and the bottom portion 46 of the casing44 is opened to drop the weight 40. As a result, the buoyancy acts onthe whole apparatus due to the function of the buoyant chambers 70, andthe whole apparatus floats to the surface of the sea automatically, thusproducing compressed air.

Operation of the apparatus shown in FIG. 3 will now be described.

The air inlet valve 28 of the container body 10 is opened and the weight40 is attached to the lower plate 22. When the apparatus with the upperplate 21 directed upward is hung by a crane (not shown), airautomatically flows into the air chamber 12 of the container body 10through the air inlet valve 28 owing to the function of the weight 40 toexpand the container body 10 into a cylindrical configuration. Then, thevalve 28 is closed. The weight 40 is attached to the clamping device 50of the weight mounting device 42. The whole apparatus is slowly loweredonto the surface of water and separated from the crane. The wholeapparatus slowly sinks under water. When the hydraulic pressureincreases as the apparatus sinks deep under water, air in the airchamber 12 is compressed and the air chamber 12 is reduced in volume.However, the air chamber 12 is not reduced in size in the horizontaldirection because of the presence of the annular reinforcement members26, but is in the vertical direction, and consequently exhibits avertically compressed appearance as a whole. As a result, air in the airchamber 12 is compressed to an extent that the internal pressure issubstantially equal to the external hydraulic pressure, and part of thecompressed air is stored in the air recovery vessel 30. As the apparatussinks deeper, the volume of the air chamber 12 is further reduced by thehydraulic pressure and most of the air in the air chamber 12 is insertedunder pressure into the air recovery vessel 30. At the same time, aprojection 62 attached to the upper plate 21 pushes down the unlockingpin 60 mounted on the lower plate 22 to release the locked state of thelock lever 58, and the clamping portion of the holding metal piece 52 isopened by means of the biasing force of the spring body 56 to releasethe weight 40. When the weight 40 has been detached from the apparatus,the whole apparatus begins to float upwardly due to the function of therecovery vessel 30. At this time, since the recovery vessel 30 keeps ahigh pressure due to the provision of the check valve 32, it is liftedby the crane when it finally floats on the surface of the water. Whenthe air inlet valve 28 is opened, air flows into the air chamber 12 torestore the apparatus to its original shape. By repeating the aboveprocesses without removing the air recovery vessel 30 from the containerbody 10, the amount of compressed air corresponding to the volume of therecovery vessel 30 can be recovered.

FIGS. 4 and 5 show a water pumping apparatus for use in hydroelectricpower generation utilizing the compressed air produced by theaforementioned compressed air production apparatus.

The water pumping apparatus of FIG. 4 comprises a container 84 disposedbetween an upstream water reservoir 80 of a hydroelectric powergenerating apparatus (not shown) and a downstream water reservoir 82 forreserving used water. The interior of the container 84 is divided intoan upper water tank chamber 88 and a lower air expansion chamber 90 by apiston 86 which is slidable in the vertical direction within thecontainer 84. The water tank chamber 88 is connected to a water inlettube 92 for flowing water into the water tank chamber 88 from thedownstream water reservoir 82 and also to a water feed tube 94 forfeeding under pressure the water reserved in the chamber 88 to theupstream water reservoir 80. The air expansion chamber 90 is providedwith an air recovery vessel 30 containing compressed air for pushing upthe piston 86 in order to expand the volume of the air expansion chamber90. The recovery vessel 30 contains the compressed air recovered by theaforementioned compressed air producing apparatus. Between the airrecovery vessel 30 and the air expansion chamber 90, a first controlvalve 96 is disposed. By adjusting the first control valve 96, theamount of compressed air to be discharged into the air expansion chamber90 from the recovery vessel 30 is regulated. In FIG. 4, referencenumeral 98 denotes a second control valve disposed at the water inlettube 92, numeral 100 denotes a third control valve disposed at the waterfeed tube 94, and numeral 102 denotes a fourth control valve disposed atan air vent pipe. These valves are operated to control the flow of wateror air.

The water pumping apparatus of FIG. 5 comprises a container 110 disposedbetween an upstream water reservoir 80 of a hydroelectric powergenerating apparatus (not shown) and a downstream water reservoir 82 forreserving the used water. The interior of the container 84 is divided bya partition wall 112 into a water tank chamber 114 and an air expansionchamber 116, which chamber communicate with each other at the lower partof the container 110. The water tank chamber 114 is connected to a waterinlet tube 92 for flowing water into the water tank chamber 114 from thedownstream water reservoir 82 and also to a water feed tube 94 forfeeding under pressure the water reserved in the chamber 114 to theupstream water reservoir 80. The air expansion chamber 116 is providedwith a recovery vessel 30 containing compressed air for expanding thevolume of the air expansion chamber 116. The apparatus of FIG. 5 isdesigned such that air bubbles of the compressed air to be dischargedinto the container 110 from the recovery vessel 30 rise upward by meansof buoyancy and are pooled in the air expansion chamber 116 divided bythe partition wall 112. The remaining construction thereof is the sameas that of the apparatus of FIG. 4.

The operation of the water pumping apparatus shown in FIGS. 4 and 5 willbe described.

First, used water, i.e. water already subjected to hydroelectricgeneration, is caused to flow into the water tank chamber 88 or 114 fromthe downstream water reservoir 82 through the water inlet tube 92 untilthe water tank chamber 88 or 114 is filled with the water. The air inthe air expansion chamber 90 or 116 is all drafted by opening the fourthcontrol valve 102. The second and fourth control valves 98 and 102 areclosed, while the third control valve 100 is opened. The first controlvalve 96 of the recovery vessel 30 is mounted to air expansion chamber90 or 116 in a slightly open state. The apparatus of FIG. 4 represents acase where the piston is used. Since the pressure of compressed airdischarged from the recovery vessel 30 is much greater than thehydraulic pressure in the water tank chamber 88, it pushes the piston 86upward. The apparatus of FIG. 5 represents a case where the piston isnot used. Air bubbles of the compressed air discharged from the recoveryvessel 30 rise in the water filled in the water tank chamber 114 whileexpanding its volume and are pooled in the air expansion chamber 116. Ineither case, the volume of the air expansion chamber 90 or 116 isgradually increased. Water rises through the water feed tube 94 by theamount equivalent to the increased volume of the air expansion chamber.When the tube 94 has been filled with water, the water flows into theupstream water reservoir 80. When the discharge of the compressed airfrom the recovery vessel 30 has been substantially stopped, the thirdcontrol valve 100 is closed and the fourth control valve 102 is openedto draft air, and the second control valve 98 is opened to introduce thewater which has already been subjected to hydroelectric power generationinto the water tank chamber 88 or 114. When all air in the air expansionchamber 90 or 116 has been drafted, the second and fourth control valves98 and 102 are closed, a new recovery vessel 30 is attached, the thirdcontrol valve 100 is opened and then the aforementioned procedure isrepeated. By repeating the aforementioned procedure, water which hasalready been subjected to hydroelectric power generation can be sentback to the upstream water reservoir 80, so that it can be repeatedlyused for hydroelectric power generation.

Although the present invention has been described in the form of thepreferred embodiments, it should be noted that the invention is notlimited to the preferred embodiments.

What is claimed is:
 1. An apparatus for compressing air, comprising:acontainer, said container defining an air chamber therein that iscapable of having its volume reduced by external hydraulic pressure; arecovery vessel connected to said container by a check valve forrecovering compressed air produced when the volume of said chamber isreduced by hydraulic pressure; and means for sinking said container andsaid recovery vessel under water, said means comprising a weightattached to said container.
 2. The apparatus of claim 1, and furthercomprising means for detaching said weight from said container when thevolume of said air chamber has been reduced a predetermined maximumamount by the hydraulic pressure.
 3. The apparatus of claim 2, andfurther comprising a buoyant body connected to said container to raisesaid container and said recovery vessel by buoyancy after said weighthas been released.
 4. The apparatus of claim 2, wherein said means fordetaching comprises a clamping device that is automatically operated todetach said weight when said air chamber has been reduced thepredetermined maximum amount.
 5. The apparatus of claim 4, wherein:saidcontainer has a piston slidable therein, said piston dividing saidcontainer into said air chamber and a water chamber; and said waterchamber has a plurality of inlet ports to allow water to flow therein,whereby hydraulic pressure can displace said piston to reduce the volumeof said air chamber.
 6. The apparatus of claim 5, wherein said weight isprovided inside an openable weight mounting device opened by openingsaid clamping device of said means for detaching.
 7. The apparatus ofclaim 6, wherein said means for detaching further has a lock leverlocking said clamping device in a closed position and an unlocking pinextending into said container for engaging said lock lever to open saidclamping device upon engagement of said locking pin by said piston. 8.The apparatus of claim 4, wherein said container is unidirectionallyexpandable and contractable under hydraulic pressure.
 9. The apparatusof claim 8, wherein said weight is provided inside an openable weightmounting device opened by opening said clamping device of said means fordetaching.
 10. The apparatus of claim 9, wherein said means fordetaching further has a lock lever locking said clamping device in aclosed position and an unlocking pin extending into said container forengaging said lock lever to open said clamping device upon engagement ofsaid locking pin by a portion of said container due to contractionthereof.
 11. The apparatus of claim 1, wherein:said container has apiston slidable therein, said piston dividing said container into saidair chamber and a water chamber; and said water chamber has a pluralityof inlet ports to allow water to flow therein, whereby hydraulicpressure can displace said piston to reduce the volume of said airchamber.
 12. The apparatus of claim 1, wherein said container isunidirectionally expandable and contractable under hydraulic pressure.13. An apparatus for compressing air, comprising:a container, saidcontainer defining an air chamber therein that is capable of having itsvolume reduced by external hydraulic pressure; a recovery vesselconnected to said container by a check valve for recovering compressedair produced when the volume of said chamber is reduced by hydraulicpressure; a weight connected to said container and said recovery vessel;and a release mechanism for automatically releasing said weight aftersaid air chamber has been reduced in volume a predetermined amount. 14.The apparatus of claim 13, and further comprising a buoyant bodyconnected to said container to raise said container and said recoveryvessel by buoyancy after said weight has been released.
 15. Theapparatus of claim 13, wherein:said container has a piston slidabletherein, said piston dividing said container into said air chamber and awater chamber; and said water chamber has a plurality of inlet ports toallow water to flow therein, whereby hydraulic pressure can displacesaid piston to reduce the volume of said air chamber.
 16. The apparatusof claim 13, wherein said container is unidirectionally expandable andcontractable under hydraulic pressure.
 17. A method of compressing air,comprising:sealing air in a container that is capable of having itsvolume reduced by external hydraulic pressure; attaching a weight havinga larger specific gravity than water to the container to sink thecontainer under water; transferring, under pressure, compressed airproduced by hydraulic pressure reducing the volume of the containerthrough a check valve and into a recovery vessel connected to thecontainer; separating the weight from the container to cause buoyancy tocause the container to rise and float on the water; and recovering thecompressed air from the recovery vessel.